I am working on a metric collector which uses Micrometer and we've decided to use it as a serverless function due to the nature of the metrics it is collecting.
We are using Kotlin with Spring Cloud Functions and the AWS Adapter.
We have a very simple function using the the Bean method from the docs. In Micrometer, the metrics are usually sent on a schedule based on a configured step (1m, 30s etc).
However, because this is a serverless function we want to send them as the Lambda is invoked obviously - I've attempted to do this by listening on the ContextClosedEvent from Spring where I manually close the Micrometer registry which sends the metrics to our backend.
When doing this I expected that there would be a new/different context for each lambda invocation but it looks like after the initial cold-start, the warm-start invocations look like they share some context, or that context isn't being re-created/instantiated on the invocations?
Can you offer an insight into if this is the case and expected outcome and perhaps a potential more reliable way to close the micrometer registry as this current pattern can cause metrics to be dropped as the context doesn't always exist and therefore the Micrometer registry is closed.
Thanks!